Venezuela's health system is sinking into further disarray, a survey led by the opposition-dominated Congress showed on Monday, with most hospitals plagued by water outages, unable to feed patients and lacking even basic devices like catheters.

In the midst of a crushing economic crisis that has caused medicine shortages and emigration of doctors, President Nicolas Maduro's socialist government has stopped issuing weekly bulletins on health.

To fill the gap, Venezuela's Congress and a health group have for five years asked doctors and hospital workers to report the situation in their institutions. Those in government-run hospitals have usually been ordered to keep quiet, and so communicate surreptitiously with the pollsters.

"The government has decided not to inform, to hide the truth. The truth is that every day Venezuelans are dying due to lack of supplies and medicines," said opposition lawmaker and oncologist Jose Manuel Olivares as he presented the findings on Monday.

All indicators worsened in 2018 and the private sector is increasingly hit, the survey said. Some 94 percent of x-ray units are out of service or only partially functional. Around 79 percent of hospitals have poor or in existent water service. Only 7 percent of emergency services are fully operative.

"Behind each number you see here, there is a story. There is a father, a mother, a son ... there is a Venezuelan suffering," said Olivares.

"We hope the government reflects on this. Political differences can never supersede the problems of the people."

The Information Ministry did not respond to a request for comment on the survey. The poll was conducted between March 1 and March 10. Information was drawn from 137 hospitals in 55 cities.

A nurse uses light from a phone while he looks for material in an out-of-use operating room of the Padre Justo hospital, during a blackout in Rubio, Venezuela, March 14, 2018.

A crumbling state-led economy and low global prices for oil, which is Venezuela's main export, have led to a shortage of medicine and vaccines, sparking the return of diseases that were once controlled such as diphtheria and measles.

Venezuelans suffering from chronic illnesses like cancer or diabetes are often forced to forgo treatment. Transplant patients who had gotten a second shot at life are terrified as anti-rejection medicine runs short, heightening chances that their body will reject the foreign organ. Epileptic patients are struggling with seizures due to drug shortages.

Amid the dire panorama, patients and health groups have been lobbying for international aid. But Maduro's government says there is no humanitarian crisis in Venezuela and has refused to accept aid.